Expandable distributed core architectures having reserved interconnect bandwidths

ABSTRACT

A network system for an expandable distributed core architecture (“DCA”) includes multiple spine switches, multiple leaf switches coupled thereto, and a plurality of interconnections coupling each of the spine switches to each of the leaf switches. Servers, storage, and other system items and resources can be coupled to the leafs via downlinks and uplinks. Each of the plurality of spine switches includes at least one unused spine port that is reserved for a future expansion of the DCA in order to accommodate the addition of at least one other separate leaf switch to the at least one unused spine port. Additional ports can be unused and reserved for future expansion additions of more leafs and/or more spines. Also, a computing system assists in the design of the specific number and configuration of spines, leafs and interconnections based upon user inputs regarding current and future system needs.

TECHNICAL FIELD

The present invention relates generally to data communication networks,and more particularly to data communication network architectures thatinvolve the use of distributed cores.

BACKGROUND

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information, and mayinclude one or more computer systems, data storage systems, andnetworking systems.

As the demands for throughput in computing systems, networks and datacenters increase, there have been a number of advancements in the waythat such systems are designed and built. While traditional data centerarchitectures typically use a monolithic, chassis-based core with a twolayer or three layer design, the use of a distributed core has becomemore prevalent of late. A distributed core architecture (“DCA”) canreduce the burdensome hierarchy that exists with traditional data centerswitching elements, and in turn provide greater scalability, higherbandwidth, and higher resiliency non-blocking communications forcomputing and storage nodes.

One problem with using distributed cores, however, is that a distributedcore architecture is often determined in a customized fashion for animmediate specific application, with an appropriate number of spineswitches, leaf switches, connections and other system components thenbeing provided and constructed to suit that specific application. Whenit then later becomes desirable to expand the number of ports,throughput or some other relevant feature for that specific distributedcore architecture, however, then another substantial customizeddetermination is made.

This added customized determination can take into account the existingsystem components and configuration, as well as what added features areneeded, upon which additional spines, leafs, connections, ports and thelike are added and rerouted to arrive at the new architecture. Thisprocess is typically customized for each given application andexpansion, and as such can involve a significant amount of effort inrecalculation and reconfiguration. Further, the possible need for evenone or two additional spines and/or leafs or a quick reconfigurationthat adds unnecessary spines and/or leafs can result in significantinconveniences or added costs.

Although many systems and methods for providing distributed corearchitectures for use in data centers and networks have generally workedwell in the past, there is always a desire for improvement. Inparticular, what is desired are systems and methods that providedistributed core architectures that are readily expandable with minimalrecalculation and reconfiguration efforts, and that are able to add theexact minimal number of additional spines and leafs that are needed.

SUMMARY

It can be an advantage of the present invention to provide improvedinformation handling systems and methods that utilize more readilyexpandable distributed core architectures. Such improved systems andmethods preferably result in expansions that can be made with minimalrecalculation and reconfiguration efforts, such that the exact minimalnumber of additional spines and leafs that are needed are actuallyadded. In particular, the various systems and methods provided hereincan involve DCAs having spine switches and/or leaf switches that haveunused ports which are reserved for future use. In such arrangements,the unused ports can be used in the future to attach additional spinesand/or leafs as may become needed. Current configurations of a DCA canbe designed so as to be accommodating of what is needed in the future,such that the current wire mapping need not be disturbed when newswitches are added during expansion. Such future and accommodatingcurrent configurations can be calculated using a distributed coremanager or other software tool, program or module.

In various embodiments of the present invention, a distributed corenetwork system can include a plurality of spine switches, each having aplurality of spine ports and being adapted to facilitate the transmittalof network data, a plurality of leaf switches coupled to said pluralityof spine switches, each having a plurality of leaf ports and beingadapted to facilitate the transmittal of network data therethrough, anda plurality of interconnections coupling each of the spine switches viaits spine ports to each of the leaf switches via its leaf ports. Each ofthe plurality of spine switches can include at least one unused spineport that is reserved for a future expansion of the distributed corenetwork in order to accommodate the addition of at least one otherseparate leaf switch to the at least one unused spine port. Similarly,leaf switches can include at least one unused leaf port that is reservedfor a future expansion of the distributed core network in order toaccommodate the addition of at least one other separate spine switch tothe at least one unused leaf port. More than one leaf and/or spineswitch can be added during expansion in this manner.

In various embodiments, the plurality of interconnections is adapted torequire no adjusting upon the addition of the at least one otherseparate leaf switch. This plurality of interconnections can include aplurality of cables, and the plurality of interconnections can utilizean OSPF interconnect protocol. In addition, said plurality of leafswitches can each further include a plurality of user ports adapted tocouple with one or more downlinked system components. In variousembodiments, the system can include this plurality of downlinked systemcomponents coupled to the plurality of user ports on the plurality ofleaf switches. In addition, the distributed core network can be adaptedto facilitate communications between each pairing of said plurality ofdownlinked system components that are coupled to different leaf switchesby using one or more spine switches between the respective leafswitches. Also, the plurality of leaf switches can further include oneor more user ports adapted to couple with one or more uplinked systemcomponents or network connections.

In various embodiments, the subject distributed core network system canfurther include a computing system that assists in the design of thespecific number and configuration of spine switches, leaf switches, andinterconnections based upon user inputs. Such user inputs can includethe number of user ports that are currently needed and the number ofuser ports that will be needed in the future, among other possibleparameters or needs.

In various further embodiments of the present invention, a computingsystem adapted to implement an expandable distributed core architecturecan include a plurality of input and output devices adapted to acceptuser inputs and provide computed outputs regarding the expandable DCA,wherein the expandable DCA includes a plurality of spine switches, aplurality of leaf switches, and a plurality of interconnections couplingthe spine switches to the leaf switches, a processor adapted to processthe user inputs according to a provided set of instructions to arrive atthe computed outputs regarding the expandable DCA, and one or moremodules adapted to be executed with respect to said processor. The oneor more modules can be software, and can contain computer code adaptedto facilitate accepting inputs from a user regarding desired featuresfor the expandable DCA, to generate an output DCA configuration usingthe user inputs, and to facilitate providing the output DCAconfiguration to the user.

As in the foregoing embodiments, the user inputs can include the numberof user ports that are currently needed and the number of user portsthat will be needed in the future. Further, the output DCA configurationcan include at least one open port on each of the plurality of spineswitches, whereby at least one new leaf switch can be added later to theexpandable DCA. Also, the output DCA configuration can include a wiremapping for the plurality of interconnections that requires no adjustingupon the addition of one or more new leaf switches, one or more newspine switches, or both. The one or more modules can include a designmodule, a build module and a run module.

In still further embodiments, various methods of implementing anexpandable distributed core architecture having reserved interconnectbandwidths can be provided. Such methods can include the process stepsof accepting user input regarding parameters for an expandable DCAhaving a plurality of spine switches, a plurality of leaf switcheshaving a plurality of user ports, and a plurality of interconnectionscoupling the leaf and spine switches, wherein the parameters includerequired features for a current DCA and required features for anexpanded DCA, designing an expanded DCA configuration based on therequired features for an expanded DCA, designing a current DCAconfiguration based on the expanded DCA configuration and the requiredfeatures for a current DCA, wherein the current DCA configurationincludes at least one open port on each of the plurality of spineswitches to provide for expansion by at least one new leaf switch, andproviding the current DCA configuration to the user.

Again, the user input can include the number of user ports that arecurrently needed and that will be needed in the future. Also, the stepof designing a current DCA configuration can include generating aphysical wire mapping that specifically couples the plurality of spineswitches to the plurality of leaf switches via the interconnections.Further, the current DCA configuration can include at least one directinterconnection between every spine switch and every leaf switch.

Other apparatuses, methods, features and advantages of the inventionwill be or will become apparent to one with skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional systems, methods, features andadvantages be included within this description, be within the scope ofthe invention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The included drawings are for illustrative purposes and serve only toprovide examples of possible structures and arrangements for thedisclosed inventive expandable distributed core architecture based datanetwork devices, systems and methods. These drawings in no way limit anychanges in form and detail that may be made to the invention by oneskilled in the art without departing from the spirit and scope of theinvention.

FIG. 1A illustrates in block diagram format the layout of an exemplaryspine and leaf arrangement to form a distributed core fabric.

FIG. 1B illustrates in block diagram format the layout of a largerexemplary distributed core architecture having spines, leafs andservers.

FIG. 2 illustrates in block diagram format the layout and developmentprogression of an exemplary distributed core architecture adapted toexpand in a streamlined fashion according to one embodiment of thepresent invention.

FIG. 3 illustrates in block diagram format the layout and developmentprogression of an alternative exemplary distributed core architectureadapted to expand a greater amount in a streamlined fashion according toone embodiment of the present invention.

FIG. 4 illustrates in block diagram format an exemplary computing systemhaving a software tool adapted to configure an expandable distributedcore architecture according to one embodiment of the present invention.

FIG. 5 provides a flowchart of an exemplary method of implementing acustomized expandable distributed core architecture having reservedinterconnect bandwidths according to one embodiment of the presentinvention.

DETAILED DESCRIPTION

Exemplary applications of apparatuses and methods according to thepresent invention are described in this section. These examples arebeing provided solely to add context and aid in the understanding of theinvention. It will thus be apparent to one skilled in the art that thepresent invention may be practiced without some or all of these specificdetails. In other instances, well known process steps have not beendescribed in detail in order to avoid unnecessarily obscuring thepresent invention. Other applications are possible, such that thefollowing examples should not be taken as limiting. In the followingdetailed description, references are made to the accompanying drawings,which form a part of the description and in which are shown, by way ofillustration, specific embodiments of the present invention. Althoughthese embodiments are described in sufficient detail to enable oneskilled in the art to practice the invention, it is understood thatthese examples are not limiting, such that other embodiments may beused, and changes may be made without departing from the spirit andscope of the invention.

For purposes of this disclosure, an information handling system mayinclude an instrumentality or aggregate of instrumentalities operable tocompute, classify, process, transmit, receive, retrieve, originate,switch, store, display, manifest, detect, record, reproduce, handle, orutilize any form of information, intelligence, or data for business,scientific, control, or other purposes. For example, an informationhandling system may be a personal computer, a network storage device, orany other suitable device, and may vary in size, shape, performance,functionality and price. The information handling system may includerandom access memory (“RAM”), one or more processing resources such as acentral processing unit (“CPU”) or hardware or software control logic,read only memory (“ROM”), and/or other types of nonvolatile memory.Additional components of the information handling system may include oneor more disk drives, one or more network ports for communicating withexternal devices, as well as various input and output (“I/O”) devices,such as a keyboard, a mouse, and a video display. The informationhandling system may also include one or more buses operable to transmitcommunications between the various hardware components.

The present invention relates in various embodiments to devices, systemsand methods involving information handling systems. In particularembodiments, the subject information handling devices, systems ormethods utilize distributed core architectures and features thereof.Such distributed core architectures can include the use of spines,leafs, interconnections therebetween, and external uplinks anddownlinks, among other hardware components. In addition, varioussoftware and firmware components can be included with the subjectdistributed core architectures. A wide variety of software protocols,platforms and programs can be used, and it is specifically contemplatedthat any suitable protocol, platform or program can be used with thesystems and methods set forth herein. Such a system can be known as aData Fabric Network Management System, among other possibilities. Asspecific non-limiting examples, software components such as the Indigo,Distributed Core Manager/DCM, or Dell Fabric Orchestrator softwareinfrastructures provided by Dell Force10 of San Jose, Calif. can beused, among other possibilities.

In various embodiments, one or more subject software infrastructures,programs or modules can provide for a specific reservation of interlinkor fabric bandwidth. Such a reservation can be initially determined byrequesting user inputs with respect to immediate and future needs forports, bandwidths, oversubscription ratios and other possible factors.Various methods for determining fabric for a given set of user ports canrange from reserving the maximum possible fabric required in a fullypopulated configuration to creating a topology that satisfies therequirements for a given oversubscription ratio and number of user portsthat cannot be expanded further. Both a sizing tool and a configurationgenerator can take the appropriate input to allow for future expansionon a given distributed core architecture (“DCA”). These tools can alsoassist in growing the distributed core from an initial or currentconfiguration to a larger or even maximum configuration for the providedinputs.

Distributed core architectures are typically specific purpose-built,high-performance networking fabrics capable of scaling up to 160+ Tbpsor more. Often referred to as a “leaf-spine architecture,” a DCA canemploy two types of nodes—a leaf node switching component or “leaf” thatconnects servers or top-of-rack elements, and a spine node switchingcomponent or “spine” that connects switches. When configured properly, a3-stage Clos network can be derived from the leaf-spine system, whichcan provide extremely low-latency and non-blocking performance betweenany two ports of the fabric.

There can be several significant advantages to a DCA arrangement. Forone thing, costs can be significantly reduced by using multiple low-costEthernet switches as opposed to traditional and expensive chassis-basedsystems. There can be full bisectional bandwidth for communicationacross any port to any port, and any host can communicate with any otherhost in the network at the full bandwidth of its network interface.Further, the system can be resilient in that nodes can be restarted orreplaced without losing the entire switching fabric.

Turning first to FIG. 1A, an exemplary spine and leaf arrangementforming a distributed core fabric is illustrated in block diagramformat. System 1 includes a number of spines 2 that are each coupled toeach of a number of leafs 3 in a distributed fashion through a pluralityof interconnects. Each spine 2 and leaf 3 can be a system node within adistributed core fabric, with various servers, storage items and/orother additional system components (not shown) being coupled to eachleaf. Each spine and leaf can also be any of a number of possiblehardware items, such as, data center networking switches. As specificnon-limiting examples, either of the S4810 or Z9000 networking switchesprovided by Dell Force10 of San Jose, Calif. can be used, although otherswitches or suitable components could also be used. A particular highend data center network switch, which can be, for example, the S4810among other possibilities, can be a single rack unit system capable ofsupporting 48 1 GbE and 4 40 GbE ports or 64 10 GbE ports. It requires350 watts of power and enables a number of non-blocking orover-subscribed distributed core designs. Another particular high enddata center network switch, which can be, for example, the Z9000 amongother possibilities, can be a two rack unit system capable of supporting32 40 GbE ports or 128 10 GbE ports and requires 800 watts of power. TheZ9000 can support up to 64 spine nodes and 128 leaf nodes to create a160 Tbps core in an extremely small power and cost footprint. In variousembodiments, every spine can be the same or a similar component, whileevery leaf can be the same or a similar component.

Continuing with FIG. 1B, a larger exemplary distributed corearchitecture having spines, leafs and servers is similarly shown inblock diagram format. Distributed core system 10 includes a number ofspines 20 that are each coupled to each of a number of leafs 30 in adistributed fashion through a plurality of interconnects 25. Suchinterconnects 25 between spines 20 and leafs 30 can be arrangedaccording to an Open Shortest Path First (“OSPF”) protocol, for example.In some embodiments, every spine 20 connects to every leaf 30. In turn,every leaf 30 is coupled to various system components 40 through aplurality of uplinks and/or downlinks 35. Such uplinks and/or downlinkscan be to one or more servers, storage items and/or other components,and can be made by way of one or more WANs, VLANs, LANs, other networkconnections and the like.

For a given distributed core system 10 having a plurality of servers,storage components and other network items that are to beinterconnected, there can be an enormous number of configurationsinvolving different switching components and routing possibilities for aswitching fabric or network core situated therebetween. As will bereadily appreciated, the vast majority of such configurationpossibilities are less than optimal due to higher costs, lowerthroughputs, slower speeds, and so forth. Ideal or near idealconfigurations will include a minimal amount of switches and routingcomponents, as well as a specific arrangement of routing interconnectstherebetween. Such configurations are often designed using a systemsoftware tool or program that can output a particular outcome orarrangement for a given set of system requirements, such as a desirednumber of uplinks, number of downlinks, bandwidth, oversubscriptionratio, and/or other system parameters.

For example, where a user might desire a system having 250 downlinks, 4uplinks, an oversubscription ratio of 1, and a specific model of lightswitch to serve as both the spines and leafs for the system, a systemtool or program might accept user inputs to such effect and specify agood or optimal configuration having 2 spine switches, 4 leaf switches,and one or more particular direct link interconnects between each spineand leaf. The combined number of downlinks and uplinks can be spreadacross the total of 4 leaf switches. This specific configuration,however, is often not optimal with respect to being able to take theexisting system and readily expand it to include additional ports,increased bandwidth and/or other system parameters in the event ofincreased needs or demands in the future for the overall system user. Assuch, the system tool or program is preferably adapted to account forfuture expansion of the system at the time an initial systemconfiguration is determined. These future expansion parameters can alsobe input to the system tool or program in terms of the number of ports,bandwidth and other items that are thought to be needed in the future,such that the configuration output for the present is designed to beable to expand up to that which is specified for the future.

Moving next to FIG. 2, the layout and development progression of anexemplary distributed core architecture adapted to expand in astreamlined fashion is provided in block diagram format. DCA 100includes two spine switches 111, 112 and two leaf switches 121, 122.This system architecture can be arranged so as to support in apreferable manner the number of ports, bandwidth, oversubscription ratioand other parameters that were specified by a user prior to forming thesystem. That is, there are preferably no more spines, leafs, otherswitches, connections or other system components present than areneeded, with the overall system having suitable amounts of bandwidth andoversubscription, preferably in an OSPF arrangement. In addition, DCA100 is further configured such that a number of ports, bandwidth andother system resources are reserved for future expansion, as indicatedby the dotted line box next to leaf switch 122.

Upon expansion, DCA 100 can become DCA 101 at some later time. As onenon-limiting example, a set of future expansion parameters specified bya user can result in DCA 100 being adapted to expand from two spines andtwo leafs to two spines and four leafs. Such expansion preferablyinvolves no significant changes to any of spine switches 111, 112, anyof existing leaf switches 121, 122, or any of the interconnectstherebetween. Rather, such expansion can involve simply adding two newleaf switches 123, 124 and interconnecting these switches with both ofexisting spine switches 111, 112. Such interconnecting can preferablyinvolve the use of existing unused ports on spines 111, 112 specificallyreserved for expansion. Such reservations and wiring arrangements couldbe made by the system tool or program.

Continuing with FIG. 3, the layout and development progression of analternative exemplary distributed core architecture adapted to expand agreater amount in a streamlined fashion is similarly shown in blockdiagram format. Similar to the foregoing embodiment of FIG. 2 above,original DCA 200 includes two spine switches 211, 212 and two leafswitches 221, 222. Again, this system architecture can be arranged so asto support in a preferable manner the number of ports, bandwidth,oversubscription ratio and other parameters that were specified by auser prior to forming the system. That is, there are preferably no morespines, leafs, other switches, connections or other system componentspresent than are needed, with the overall system having suitable amountsof bandwidth and oversubscription, preferably in an OSPF arrangement.Also similar to the foregoing embodiment, DCA 200 is further configuredsuch that a number of ports, bandwidth and other system resources arereserved for future expansion, as indicated by the dotted line boxesnext to leaf switch spine switch 212 and leaf switch 222.

Unlike the foregoing embodiment, however, DCA 200 is configured for alarger expansion. That is, DCA 200 can become DCA 201 at some later timeupon expansion. As another non-limiting example, a set of futureexpansion parameters specified by a user can result in DCA 200 beingadapted to expand from its original two spines and two leafs to fourspines and six leafs, which would then support a significant increase inavailable ports and bandwidth. Similar to the foregoing example, suchexpansion preferably involves no significant changes to any of existingspine switches 211, 212, any of existing leaf switches 221, 222, or anyof the interconnects therebetween. Rather, such expansion can involveadding two new spine switches 213, 214, adding four new leaf switches223, 224, 225, 226, and interconnecting these new switches with theexisting spine switches 211, 212 and leaf switches 221, 222. Suchinterconnecting can preferably involve the use of existing unused portson the existing switches that were specifically reserved for expansion.Again, such reservations and wiring arrangements could be made by thesystem tool or program upon the design and configuration of original DCA200.

Turning next to FIG. 4, an exemplary computing system having a softwareprogram or tool adapted to configure an expandable distributed corearchitecture is illustrated in block diagram format. An overalldistributed core network system 400 can include a computing system 300adapted to design one or more expandable DCAs, as well as at least oneactual expandable DCA 200 itself. A given expandable DCA 200 can becustomized, or can be a standardized solution to a relatively common setof input parameters, as may be applicable. In this particular example,the illustrated expandable DCA 200 can be that of the foregoing examplein FIG. 3, although it will be readily appreciated that any otherexpandable DCA could be used.

A computing system adapted to design, build and run one or moreexpandable DCAs can include a hardware portion 360 as well as a softwareor program tool portion 370. The hardware portion 360 can include anysuitable general or special purpose computer having one or moreprocessors, storage components and peripherals, as will be readilyappreciated. Peripherals can include input devices such as a keyboard,mouse, microphone, buttons, disk drive, data line, and/or other inputitems, as well as output devices such as a video monitor, speakers, diskdrive, data line and/or other output components. The software portion370 can include one or more proprietary programs or modules adapted torun on a variety of different computing platforms. Software portion 370can include various features adapted to accept input from and provideoutput to a user, such as through the use of a graphical user interface(“GUI”) on a video monitor or other similar hardware display.

Software portion 370 can include one or more programs that can be calledany of a variety of things, such as, for example, a pre-sale calculationprogram, a configuration tool, or a Distributed Core Manager (“DCM”),among other possibilities. This DCM or tool 370 can include a number ofmodules or components, such as, for example, a Design module orsub-process 372, a Build module or sub-process 374, and a Run module orsub-process 376. Each of these different modules, components orsub-processes can have its own set of functions and parameters, and eachone can potentially be provided separately, or all bundled together as asingle tool or program offering.

Design module 372 can be a program or component that calculates thenumber of spine switches, number of leaf switches, and interconnectedwire mapping that are needed based on various input data items, such as,for example, planned uplink ports, future uplink ports, planned downlinkports, future downlink ports, oversubscription ratio, downlink IPaddress/prefix and protocol profile, and/or downlink VLAN ID, amongother possible user inputs or designations. After a calculation iscomputed, then this configuration tool or design module 372 can generatean outcome in a suitable format, such as, for example, a comma separatedvalues (“CSV”) file, Excel or other spreadsheet, or other appropriateusable output of computed result simulated data across the fabric. TheCSV file or other output can contain information on the number and typesof switches, number and types of ports, number and types of optics,number and types of cables, oversubscription ratio, and/or otherpertinent data for a given DCA.

This calculation tool or design module 372 can indicate what is neededfor an initial deployment of the given DCA that allows the currentrequirements to be met, as well as the required amount of spine andinterlink ports that are reserved for future expansion. Again, in termsof such future expansion, the amount of spine and interlink ports thatare reserved can depend upon the initial settings, as well as the calledout maximum number of user and downlink ports that are specified for thefuture expansion. After a suitable configuration is computed given theplanned and future ports, bandwidths and other input parametervariables, the design module 372 can preferably provide an initialnumber of spines and leafs, as well as a physical wire mapping thatresults in the performance that is initially needed while reservingports and bandwidth for future expansion in a way that is readily andeasily accomplished.

Build module 374 can be a program or component that utilizes a givenoutput of the design module 372 to help build a respective DCA. Variousfunctions or features of this build module 374 can include inputting orassociating an input management IP address pool, loading the CSV file orother suitable output from the design module 372, generating anappropriate dynamic host configuration protocol (“DHCP”) configurationfile, generating a configuration file, transmitting the configurationinto a receiving server, such as an FTP/sFTP or TFTP server, sending arequest to discover a suitable node, and validating the plan anddiscovery configurations to report the result into the appropriatedatabase. In the event that the input wiring matching does not match,then a new wiring mapping can be provided. Also, if the configurationwith the noted protocol does not match, then the CSV or other suitableoutput file could also be provided. This could include, for example, oneor more error messages regarding wiring information between one or morespines and one or more leafs.

Run module 376 can be a program or component that then runs with thebuilt configuration after it is actually put online. This run module canbe adapted to monitor the performance of the configured and built DCA,and can provide one or more statistics or vitals with respect to how theDCA is performing. As such, one or more adjustments or othertroubleshooting implementations can be more readily accomplished wherenecessary. Any suitable interface statistics could be used to debug theconnectivity flow between one or more spines and one or more leafs. Forexample, the connectivity between a spine and a leaf can be debuggedusing statistics of the respective related interfaces therebetween.

Overall, DCM 370 can provide a detailed wiring plan both in tabular andgraphical format based on the design output, the content of which can beexported to a suitable output file (e.g., CSV file) from the GUI.Separate wiring plans can be provided both for the initial or currentneed, as well as for a future expanded need. A detailed generatednetwork topology can provide a view of the distributed core based on thedesign output. A summary output can also be provided, which indicatesall of the input parameters as well as the recommended number of nodes,types, optics and cables to be procured for initial deployment based onthe current needs. Future expansion needs can be dealt with at a latertime, as may be desired.

As one particular non-limiting example, a user may designate a systemhaving 250 downlinks, 4 uplinks, an oversubscription ratio of 1, and aspecific model of light switch to serve as both the spines and leafs forthe system. The user may then also indicate that another 200 downlinkswill be needed in the future, with the same number of 4 uplinks and anoversubscription ratio of 1. The system tool or program DCM 370 mightaccept these user inputs to such effect and specify a good or optimalconfiguration having 2 spine switches, 4 leaf switches, and one or moreparticular direct link interconnects between each spine and leaf, withthe combined number of downlinks and uplinks being suitably spreadacross the total of 4 leaf switches. In addition, the DCM 370 couldindicate that a total of 4 spine switches and 8 leaf switches would beneeded when the system is expanded to have 450 downlinks.

In order to facilitate a streamlined expansion from 2/4 to 4/8spines/leafs, a plurality of ports on each spine switch and leaf switchare deliberately left open in the initial configuration and wiremapping, with such open ports then being used when the new spines andleafs are added. In various embodiments, such an addition of more spinesand leafs at a later expansion would then not involve any rewiring ofthe existing wire mapping for the original deployment. Rather, newspines, new leafs, and new interconnect wires are added according to anexpansion configuration that uses the same wiring on the originaldeployment and just adds new wiring to account for the newly addedsystem components. Such initial and later expansion wire mappings can becalculated to achieve this end using the DCM 370.

Exemplary screenshots from the software tool of FIG. 4 according to oneembodiment of the present invention can be described as follows. Onescreenshot depicts a sample display page during a design process run bythe design module 372 above. Again, such a “Design Wizard” or othersuitable software module or component can be adapted to accept userinputs and desired system parameters in order to design a DCA that iscustomized to the specific needs of the user. This can involve reviewingthe proposed design after all inputs are considered.

Another screenshot may depict a sample display page during an initialpart of a build process run by build module 374 above. In such ascreenshot, the network topology has already been determined for aspecific DCA, with the number of spines, number of leafs and graphicalwiring plan all being known. The topology provided in the GUI of whichthe screenshot being described is a part indicates wiring specificationsand notes for each port of each switch, such that a user can make thedesigned wiring connections while building the specifically designedDCA. While we have described just a couple of exemplary screenshots, itwill be readily appreciated that other types of GUI presentations arealso possible, and that similar presentations can be made to assistusers at all stages and sub-processes within the DCM 370 and its variousfunctions and features. It is specifically contemplated that all suchsuitable presentations and GUIs can be used with the systems and methodsdisclosed herein.

Although a wide variety of applications involving expanding adistributed core architecture using the foregoing systems can beenvisioned, one basic method is provided here as an example. Turninglastly to FIG. 5, a flowchart of an exemplary method of implementing acustomized expandable distributed core architecture having reservedinterconnect bandwidths is provided. In particular, such a method caninvolve using or operating a DCA manager or other computing system, suchas any of the various DCM modules, tools, programs, and associateddevices and systems described above. It will be readily appreciated thatnot every method step set forth in this flowchart is always necessary,and that further steps not set forth herein may also be included.Furthermore, the exact order of steps may be altered as desired forvarious applications. For example, some embodiments might involvedesigning some form of a current DCA configuration prior to designing anexpanded DCA configuration, such that steps 704 and 706 are reversed.Alternatively, these steps can be performed in parallel. Also, furtherintermediate steps can involve the design of an intermediate expansionconfiguration between the current and finally fully expandedconfigurations, as will be readily appreciated.

Beginning with a start step 700, user inputs regarding current andfuture system needs are accepted into the system at process step 702. Anexpanded DCA configuration is then designed, calculated or otherwisefound at process step 704, after which a current DCA configuration isdesigned at process step 706. The current DCA configuration can then beprovided to the user at process step 708, after which the current DCA,including the specific wire mapping for the interconnections, can bebuilt at process step 710.

At subsequent process step 712, the current DCA system can be monitoredwhile it is running. This can occur for as long as the current DCA isadequate for the needs of the user. At some later time, the expanded DCAand its specific wire mapping can be built and its configurationvalidated at process step 714. This expanded DCA can also be monitoredwhile it runs, with statistics and other system notes being provided asmay be desired and suitable at process step 716. The method thenproceeds to finish at end step 718. Further steps not depicted caninclude, for example, intermediate expansion designs, builds andmonitoring.

Although the foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding, itwill be recognized that the above described invention may be embodied innumerous other specific variations and embodiments without departingfrom the spirit or essential characteristics of the invention. Variouschanges and modifications may be practiced, and it is understood thatthe invention is not to be limited by the foregoing details, but ratheris to be defined by the scope of the claims.

What is claimed is:
 1. A method of implementing an expandabledistributed core architecture (“DCA”) having reserved interconnectbandwidths, the method comprising: obtaining, by a computing system,requirements for DCA operation, the requirements comprising firstrequirements for the expandable DCA and second requirements for anexpanded DCA, the first requirements specifying a number of uplink portsand a number of downlink ports for the expandable DCA, the secondrequirements specifying a number of uplink ports and a number ofdownlink ports for the expanded DCA, wherein at least one of (i) and(ii) is true: (i) the number of uplink ports for the expanded DCA ishigher than the number of uplink ports for the expandable DCA; (ii) thenumber of downlink ports for the expanded DCA is higher than the numberof downlink ports for the expandable DCA; and determining, by thecomputing system, a configuration of the expandable DCA based on thefirst and second requirements and on an optimality objective, whereindetermining the configuration comprises using the numbers of the uplinkand downlink ports for the expandable DCA and the numbers of the uplinkand downlink ports for the expanded DCA to determine a number of spineswitches for the expandable DCA, a number of leaf switches for theexpandable DCA, and direct interconnections between the spine and leafswitches for the expandable DCA; wherein the configuration is for theexpandable DCA corresponding to the first requirements but not thesecond requirements, but the configuration takes into account the secondrequirements to provide expandability of the expandable DCA to theexpanded DCA with the expanded DCA including all of the spine and leafswitches of the expandable DCA and all of the direct interconnectionsbetween the spine and leaf switches of the expandable DCA, theconfiguration requiring at least one of the spine and leaf switches ofthe expandable DCA to have at least one port that is unused in theexpandable DCA but is used in the expanded DCA; wherein the optimalityobjective comprises at least one of: low cost; high throughput; highspeed; minimal amount of switches; minimal amount of routing components.2. The method of claim 1, wherein the expandable DCA configurationincludes at least one direct interconnection between every spine switchand every leaf switch.
 3. The method of claim 1 wherein each of theexpandable and expanded DCAs includes at least one directinterconnection between every spine switch and every leaf switch.
 4. Themethod of claim 1 wherein each spine and leaf switch of the expandableDCA has a port that is unused in the expandable DCA but is used in theexpanded DCA.
 5. The method of claim 1 wherein determining saidconfiguration comprises determining a configuration that reduces a costof each of the expandable and expanded DCAs.
 6. The method of claim 1wherein determining said configuration comprises determining aconfiguration that increases throughput of each of the expandable andexpanded DCAs.
 7. The method of claim 1 wherein determining saidconfiguration comprises determining a configuration that increases speedof each of the expandable and expanded DCAs.
 8. The method of claim 1wherein determining said configuration comprises determining aconfiguration that reduces a number of the spine and leaf switches ineach of the expandable and expanded DCAs.
 9. The method of claim 1wherein determining said configuration comprises determining aconfiguration that reduces a number of routing components in each of theexpandable and expanded DCAs.
 10. The method of claim 1 wherein each ofthe first and second requirements comprises a bandwidth requirement. 11.The method of claim 10 wherein the bandwidth requirement is higher forthe expanded DCA than for the expandable DCA.
 12. The method of claim 1wherein each of the first and second requirements comprisesoversubscription ratio.
 13. The method of claim 1 wherein each of thefirst and second requirements specifies a switch model to serve as thespine and leaf switches.
 14. The method of claim 1 wherein the expandedDCA has more of the leaf switches than the expandable DCA but the samenumber of the spine switches as in the expandable DCA.
 15. The method ofclaim 1 wherein the expanded DCA has more of the leaf switches and moreof the spine switches than the expandable DCA.
 16. A computing systemcomprising: one or more processors; one or more storage components; oneor more peripherals; and a software portion stored in the one or morestorage components which, when executed by the one or more processors,causes the computing system to perform a method for implementing anexpandable distributed core architecture (“DCA”) having reservedinterconnect bandwidths, the method comprising: obtaining, by the one ormore processors, requirements for DCA operation, the requirementscomprising first requirements for the expandable DCA and secondrequirements for an expanded DCA, the first requirements specifying anumber of uplink ports and a number of downlink ports for the expandableDCA, the second requirements specifying a number of uplink ports and anumber of downlink ports for the expanded DCA, wherein at least one of(i) and (ii) is true: (i) the number of uplink ports for the expandedDCA is higher than the number of uplink ports for the expandable DCA;(ii) the number of downlink ports for the expanded DCA is higher thanthe number of downlink ports for the expandable DCA; and determining, bythe one or more processors, a configuration of the expandable DCA basedon the first and second requirements and on an optimality objective,wherein determining the configuration comprises using the numbers of theuplink and downlink ports for the expandable DCA and the numbers of theuplink and downlink ports for the expanded DCA to determine a number ofspine switches for the expandable DCA, a number of leaf switches for theexpandable DCA, and direct interconnections between the spine and leafswitches for the expandable DCA; wherein the configuration is for theexpandable DCA corresponding to the first requirements but not thesecond requirements, but the configuration takes into account the secondrequirements to provide expandability of the expandable DCA to theexpanded DCA with the expanded DCA including all of the spine and leafswitches of the expandable DCA and all of the direct interconnectionsbetween the spine and leaf switches of the expandable DCA, theconfiguration requiring at least one of the spine and leaf switches ofthe expandable DCA to have at least one port that is unused in theexpandable DCA but is used in the expanded DCA; wherein the optimalityobjective comprises at least one of: low cost; high throughput; highspeed; minimal amount of switches; minimal amount of routing components.17. The computing system of claim 16 wherein each of the first andsecond requirements comprises a bandwidth requirement.